U.S. patent application number 17/584755 was filed with the patent office on 2022-05-12 for auto detection system based on thermal signals.
The applicant listed for this patent is PixArt Imaging Inc.. Invention is credited to SEN-HUANG HUANG, CHIUNG-WEN LIN, CHIH-MING SUN, MING-HAN TSAI, WEI-MING WANG, PO-WEI YU.
Application Number | 20220146115 17/584755 |
Document ID | / |
Family ID | |
Filed Date | 2022-05-12 |
United States Patent
Application |
20220146115 |
Kind Code |
A1 |
SUN; CHIH-MING ; et
al. |
May 12, 2022 |
AUTO DETECTION SYSTEM BASED ON THERMAL SIGNALS
Abstract
There is provided an auto detection system including a thermal
detection device and a host. The host controls an indication device
to indicate a prompt message or detection results according to a
slope variation of voltage values or 2D distribution of temperature
values detected by the thermal detection device, wherein the
voltage values include the detected voltage of a single pixel or
the sum of detected voltages of multiple pixels of a thermal
sensor.
Inventors: |
SUN; CHIH-MING; (Hsin-Chu
County, TW) ; TSAI; MING-HAN; (Hsin-Chu County,
TW) ; LIN; CHIUNG-WEN; (Hsin-Chu County, TW) ;
YU; PO-WEI; (Hsin-Chu County, TW) ; WANG;
WEI-MING; (Hsin-Chu County, TW) ; HUANG;
SEN-HUANG; (Hsin-Chu County, TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
PixArt Imaging Inc. |
Hsin-Chu County |
|
TW |
|
|
Appl. No.: |
17/584755 |
Filed: |
January 26, 2022 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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16818442 |
Mar 13, 2020 |
11280500 |
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17584755 |
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16458626 |
Jul 1, 2019 |
10871394 |
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16818442 |
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62714132 |
Aug 3, 2018 |
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62887740 |
Aug 16, 2019 |
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International
Class: |
F24C 15/20 20060101
F24C015/20; G01J 5/10 20060101 G01J005/10; G01J 5/00 20060101
G01J005/00; B66B 5/00 20060101 B66B005/00; A61F 13/42 20060101
A61F013/42 |
Claims
1. An auto detection system, configured to monitor an elevator
cabin, the auto detection system comprising: a thermal detection
device configured to output digital values at a predetermined
frequency; and a host configured to receive the digital values,
calculate a slope between two digital values, identify opening and
closing of a door of the elevator cabin by comparing the calculated
slop and a slope threshold range, and calculate a fluctuation
degree of multiple digital values within a predetermined time
interval after the door is identified to be opened and then
closed.
2. The auto detection system as claimed in claim 1, wherein the
thermal detection device is further configured to output object
temperatures at the predetermined frequency, and the host is
further configured to calculate a temperature variation of the
object temperatures, and identify the elevator cabin having a
person therein in response to the calculated slope between the two
digital values exceeding the slope threshold range, the fluctuation
degree exceeding a code variation threshold, and the temperature
variation exceeding a temperature threshold.
3. The auto detection system as claimed in claim 1, wherein the
thermal detection device comprises: a single thermopile sensor
configured to generate a voltage signal at the predetermined
frequency; and an analog to digital converter configured to convert
the voltage signal to the digital signals.
4. The auto detection system as claimed in claim 1, wherein the
thermal detection device comprises: a thermopile sensor array
comprising a pixel array configured to generate multiple voltage
signals; an addition circuit configured to perform binning on the
multiple voltage signals to generate a voltage sum; and an analog
to digital converter configured to convert the voltage sum to the
digital signals.
5. The auto detection system as claimed in claim 2, wherein the
host is coupled with an indication device for indicating whether
the elevator cabin has a person therein or not via the indication
device, or coupled with a mobile device for indicating whether the
elevator cabin has a person therein or not via the mobile
device.
6. The auto detection system as claimed in claim 2, wherein the
thermal detection device is further configured to output ambient
temperatures to the host.
7. The auto detection system as claimed in claim 6, wherein the
host is further configured to adjust at least one of the slope
threshold range, the temperature threshold and the code variation
threshold according to the ambient temperatures.
8. The auto detection system as claimed in claim 2, wherein the two
digital values are two adjacent digital values outputted by the
thermal detection device, the fluctuation degree is a standard
deviation of the multiple digital values, and the temperature
variation is a difference between two adjacent object temperatures
outputted by the thermal detection device, or a difference between
a current object temperature outputted by the thermal detection
device and a reference temperature.
9. The auto detection system as claimed in claim 1, wherein the
thermal detection device has a field of view which does not cover
an entrance of the elevator cabin.
10. The auto detection system as claimed in claim 1, wherein the
predetermined time interval is 3 to 10 seconds.
11. An auto detection system, configured for stove detection, the
auto detection system comprising: a thermal detection device,
having a field of view covering the stove, the thermal detection
device comprising a thermopile sensor array configured to output a
thermal frame having multiple object temperatures; and a host,
configured to receive the multiple object temperatures, and control
a display device to show a message of reaching a target temperature
upon identifying that at least one of the multiple object
temperatures is larger than a heating threshold.
12. The auto detection system as claimed in claim 11, wherein the
host is further configured to turn on an extraction fan upon
identifying that the multiple object temperatures exceed a room
temperature threshold, and automatically adjust a wind strength of
the extraction fan according to a variation of the multiple object
temperatures exceeding the room temperature threshold.
13. The auto detection system as claimed in claim 11, wherein the
host is further configured to control the display device to show a
warning message upon identifying that the multiple object
temperatures exceed a high temperature threshold.
14. The auto detection system as claimed in claim 11, wherein the
host is configured to control the display device to show the
multiple object temperatures as a 2D image.
15. The auto detection system as claimed in claim 11, wherein the
host is further configured to switch off the stove when there is no
human body moving in the field of view for a predetermined time
interval.
16. An auto detection system, comprising: a thermal detection
device, having a field of view covering ingredients, the thermal
detection device comprising a thermopile sensor array configured to
output a thermal frame having multiple object temperatures; and a
host, configured to receive the multiple object temperatures and
control a display device to show a message of nonuniform
temperature upon identifying that uniformity of the multiple object
temperatures is lower than a uniformity threshold.
17. The auto detection system as claimed in claim 16, wherein the
host is further configured to turn on an extraction fan upon
identifying that the multiple object temperatures exceed a room
temperature threshold, and automatically adjust a wind strength of
the extraction fan according to a variation of the multiple object
temperatures exceeding the room temperature threshold.
18. The auto detection system as claimed in claim 16, wherein the
host is further configured to control the display device to show a
warning message upon identifying that the multiple object
temperatures exceed a high temperature threshold.
19. The auto detection system as claimed in claim 16, wherein the
host is further configured to control the display device to show
the multiple object temperatures as a 2D image.
20. The auto detection system as claimed in claim 16, wherein the
host is further configured to switch off a stove containing the
ingredients when there is no human body moving in the field of view
for a predetermined time interval.
Description
RELATED APPLICATIONS
[0001] The present application is a continuation application of
U.S. application Ser. No. 16/818,442, filed on Mar. 13, 2020, which
is a continuation-in-part application of an application Ser. No.
16/458,626, filed Jul. 1, 2019, which claims the priority benefit
of U.S. Provisional Application Ser. No. 62/714,132, filed on Aug.
3, 2018, and claims the priority benefit of U.S. Provisional
Application Ser. No. 62/887,740, filed on Aug. 16, 2019, the
disclosures of which are hereby incorporated by reference herein in
their entirety.
BACKGROUND
1. Field of the Disclosure
[0002] This disclosure generally relates to an auto detection
system and, more particularly, to an auto detection system that
performs the electronic device control and message prompting based
on thermal signals.
2. Description of the Related Art
[0003] In the image processing technology nowadays, it is able to
perform various automatic controls according to images acquired by
an image sensor, e.g., performing the ID recognition using images
to accordingly control the corresponding electronic devices.
[0004] However, the privacy protection is gradually considered an
important issue. Accordingly, in a public area, unless being used
as a monitor device, the image sensor is no longer suitable to be
used as an automatic control means. In addition, although a
pyroelectric infrared (PIR) motion sensor has been broadly applied
to the lamp control means as an automatic switch to save power by
turning off the lamp in an area when there is no person in that
area, the PIR motion sensor can lose its function when an object in
the detected area thereof has no motion due to that the PIR motion
sensor is essentially functioned to detect a moving object.
[0005] Accordingly, the present disclosure provides an auto
detection system without using an image sensor or a PIR motion
sensor and can be applied to the human detection in an elevator,
the urine-wet detection, the stove detection, the hair temperature
detection and the skin temperature detection.
SUMMARY
[0006] The present disclosure provides an auto detection system
that identifies whether there is a person in an elevator cabin
according to the slope of digital values, the fluctuation of
digital values and the variation of temperatures outputted by a
thermal sensor chip.
[0007] The present disclosure further provides an auto detection
system that identifies a urine-wet condition of a diaper according
to the slope of digital values outputted by a thermal sensor
chip.
[0008] The present disclosure further provides an auto detection
system that controls a display to show a 2D temperature
distribution of multiple temperature values outputted by a thermal
sensor chip as a reference for a user in cooking.
[0009] The present disclosure provides an auto detection system
configured to monitor an elevator cabin and including a thermal
detection device and a host. The thermal detection device is
configured to output digital values at a predetermined frequency.
The host is configured to receive the digital values, calculate a
slope between two digital values, identify opening and closing of a
door of the elevator cabin by comparing the calculated slop and a
slope threshold range, and calculate a fluctuation degree of
multiple digital values within a predetermined time interval after
the door is identified to be opened and then closed.
[0010] The present disclosure further provides an auto detection
system configured for stove detection and including a thermal
detection device and a host. The thermal detection device has a
field of view covering the stove, and the thermal detection device
includes a thermopile sensor array configured to output a thermal
frame having multiple object temperatures. The host is configured
to receive the multiple object temperatures, and control a display
device to show a message of reaching a target temperature upon
identifying that at least one of the multiple object temperatures
is larger than a heating threshold.
[0011] The present disclosure further provides an auto detection
system including a thermal detection device and a host. The thermal
detection device has a field of view covering ingredients, and the
thermal detection device includes a thermopile sensor array
configured to output a thermal frame having multiple object
temperatures. The host is configured to receive the multiple object
temperatures and control a display device to show a message of
nonuniform temperature upon identifying that uniformity of the
multiple object temperatures is lower than a uniformity
threshold.
[0012] In the present disclosure, the thermal sensor includes a
single thermopile sensor (i.e. outputting one voltage signal once)
or a thermopile sensor array (i.e. outputting multiple voltage
signals per frame). The thermal detection device includes an
addition circuit used to perform the binning on multiple voltage
signals outputted by multiple pixels of the thermal sensor. The
voltage sum is then processed by the analog-digital-conversion so
as to improve the signal-to-noise ratio and accuracy.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Other objects, advantages, and novel features of the present
disclosure will become more apparent from the following detailed
description when taken in conjunction with the accompanying
drawings.
[0014] FIG. 1 is a cross-sectional view of a package of thermal
sensor array according to one embodiment of the present
disclosure.
[0015] FIG. 2 is a schematic block diagram of a thermal detection
device according to one embodiment of the present disclosure.
[0016] FIGS. 3A to 3D are schematic diagrams of the pixel binning
according to some embodiments of the present disclosure.
[0017] FIG. 4 is a schematic block diagram of an auto detection
system according to one embodiment of the present disclosure.
[0018] FIG. 5 is a schematic diagram of an auto detection system
according to a first embodiment of the present disclosure.
[0019] FIG. 6 is a schematic diagram of the temperature variation
of an auto detection system according to a first embodiment of the
present disclosure.
[0020] FIG. 7A is a schematic diagram of the digital value
variation and the slope variation of an auto detection system
according to a first embodiment of the present disclosure, wherein
no person is in an elevator cabin.
[0021] FIG. 7B is another schematic diagram of the digital value
variation and the slope variation of an auto detection system
according to a first embodiment of the present disclosure, wherein
at least one person is in an elevator cabin
[0022] FIG. 8 is an operational flow chart of an auto detection
system according to a first embodiment of the present
disclosure.
[0023] FIG. 9 is a schematic diagram of an auto detection system
according to a second embodiment of the present disclosure.
[0024] FIG. 10 is an operational flow chart of an auto detection
system according to a second embodiment of the present
disclosure.
[0025] FIG. 11 is a schematic diagram of an auto detection system
according to a third embodiment of the present disclosure.
[0026] FIGS. 12A and 12B are schematic diagrams of the 2D
temperature distribution of an auto detection system according to a
third embodiment of the present disclosure.
[0027] FIGS. 13 to 16 are schematic diagrams of an optical sensor
assembly according to one embodiment of the present disclosure.
[0028] FIGS. 17 to 19 are schematic diagrams of an optical sensor
assembly according to another embodiment of the present
disclosure.
DETAILED DESCRIPTION OF THE EMBODIMENT
[0029] It should be noted that, wherever possible, the same
reference numbers will be used throughout the drawings to refer to
the same or like parts.
[0030] The present disclosure provides an auto detection system
that performs the electronic device control or the message
prompting according to voltage signals or values outputted by a
single thermopile sensor or a thermopile sensor array without using
an image sensor or a pyroelectric infrared (PIR) motion sensor
thereby solving the problems of privacy protection and steady
object detection.
[0031] Referring to FIG. 1, it is a cross-sectional view of a
package of thermal sensor array 10 according to one embodiment of
the present disclosure. The package of thermal sensor array 10
includes a circuit board 11, a sensor array integrated circuit 13,
a package 15 and a filter 17. The sensor array integrated circuit
13 has multiple sensing elements (or called pixels) 130 arranged in
a matrix, e.g., FIGS. 3A to 3D showing 8.times.8 sensing elements.
The filter 17 is used to block light spectrum outside far infrared
light. When the sensing elements 130 absorb far infrared light, a
potential difference is formed at two terminals of the element to
output a voltage signal as a detected signal. Each of the sensing
elements 130 is, for example, a thermopile sensor, wherein the
principle of a thermopile sensor that receives far infrared light
to output a voltage signal is known to the art and thus details
thereof are not described herein. Accordingly, the multiple sensing
elements 130 of the package of thermal sensor array 10 output
multiple voltage signals or voltage values to form a frame.
[0032] It should be mentioned that although FIG. 1 shows only one
set of sensor array integrated circuit 13, the present disclosure
is not limited thereto. In the case that a larger detection range
is required, the package of thermal sensor array 10 includes
multiple sets of sensor array integrated circuits 13 to output
multiple sets of voltage signals or voltage values, and details
thereof are referred to a U.S. patent application Ser. No.
16/294,873, file on Mar. 6, 2019 and entit1ed "FAR INFRARED SENSOR
APPARATUS HAVING MULTIPLE SENSING ELEMENT ARRAYS INSIDE SINGLE
PACKAGE", assigned to the same assignee of the present disclosure,
and the full disclosure of which is incorporated herein by
reference.
[0033] Referring to FIG. 2, it is a schematic block diagram of a
thermal detection device 200 according to one embodiment of the
present disclosure. The thermal detection device 200 is formed as,
for example, a chip package that is encapsulated by a casing to
form a device similar to a camera, but not limited to. The thermal
detection device 200 includes a thermal sensor 201, a row decoder
202, a column decoder (shown as col. decoder) 203, an amplifier
204, an addition circuit (shown as addition ckt.) 205, an
analog-to-digital converter (ADC) 206, a first calibration
calculating circuit 207, a second calibration calculating circuit
208, and an ambient temperature sensor (shown as ambient T sensor)
209.
[0034] The thermal sensor 201 includes, for example, the package of
thermal sensor array 10 mentioned above. According to control
signals of the row decoder 202 and the column decoder 203, voltage
signals or voltage values Vobj of every pixel are sequentially
readout (by scanning and sampling procedure) from the thermal
sensor 201, wherein the method of scanning a pixel array according
to the control signals of a row decoder and a column decoder is
known to the art and thus details thereof are not described
herein.
[0035] In the present disclosure, the thermal sensor 201 is used to
detect far infrared light generated from the object within a field
of view thereof. The ambient temperature sensor 209 is selected
from, for example, the temperature meter other than the far
infrared sensor. The ambient temperature sensor 209 is used to
detect ambient temperature surrounding the thermal detection device
200 and output voltage signals or voltage values Vamb to the ADC
206, wherein by using different types of temperature meters, the
ambient temperature sensor 209 generates a current signal at first
and then the current signal is converted to the voltage signal
Vamb. The detection frequency of the thermal sensor 201 is arranged
to be identical to or different from the detection frequency of the
ambient temperature sensor 209.
[0036] The amplifier 204 is, for example, a programmable game
amplifier (PGA) that is used to amplify the voltage signal or value
Vobj outputted by the thermal sensor 201. It should be mentioned
that although FIG. 2 shows only one amplifier 204, the present
disclosure is not limited thereto. The thermal detection device 200
includes multiple amplifiers 204 respectively coupled to one pixel
row for amplifying the voltages on the connected pixel row.
[0037] The addition circuit 205 is used to perform the binning or
summation of values of multiple voltage signals generated by the
thermopile sensor array, if being adopted, to achieve the purposes
of improving the signal-to-noise (SNR) and increasing amplitude of
the voltage signal to improve the resolution. In the present
disclosure, a pixel number or pixel region that the addition
circuit 205 performs the binning thereof is determined according to
different applications. For example, in FIG. 3A, the addition
circuit 205 performs the binning of voltage signals of all pixels
(e.g., 8.times.8 pixel array being taken as an example herein) to
obtain one voltage sum to be outputted to the ADC 206; in FIG. 3B,
the addition circuit 205 performs the binning of voltage signals of
a central 4.times.4 window and the voltage signals of other pixels
outside the 4.times.4 window is maintained as they are, e.g.,
obtaining one voltage sum associated with the 4.times.4 window and
48 voltage signals associated with every single pixel to be
outputted to the ADC 206; in FIG. 3C, the pixel array is divided
into 16 regions and the addition circuit 205 performs the binning
of 4 voltage signals at each region to obtain 16 voltage sums to be
outputted to the ADC 206; and in FIG. 3D, the pixel array is
divided into 4 regions and the addition circuit 205 performs the
binning of 16 voltage signals at each region to obtain 4 voltage
sums to be outputted to the ADC 206. It is appreciated that the
binning shown in FIGS. 3A to 3D is only intended to illustrate but
not to limit the present disclosure.
[0038] The ADC 206 is used to convert each voltage signal Vobj or
each voltage sum from the addition circuit 205 to a digital code,
each digital code has a digital value. The ADC 206 is further used
to convert the voltage signal or voltage value Vamb into the
digital signal. The ADC 206 may generate a number of digital values
associated with Vobj different from a number of digital values
associated with Vamb within the same time interval.
[0039] The first calibration calculating circuit 207 is used to
convert the digital value associated with the voltage signals
without the binning to the temperature signal, e.g., the digital
value associated with one voltage signal Vobj or Vamb corresponding
to one temperature value or the digital values associated with
multiple voltage signals Vobj or Vamb corresponding to one
identical temperature value (in the case that the resolution of
digital value being larger than the resolution of temperature
value). The thermal detection device 200 preferably further has a
memory 210 used to previously record the corresponding relationship
or algorithm between the digital value (or digital code) and the
temperature value such that when the digital value of one voltage
signal Vobj or Vamb is received from the ADC 206, a corresponding
temperature value Tobj or Tamb is calculated by the first
calibration calculating circuit 207.
[0040] The second calibration calculating circuit 208 is used to
convert the digital value associated with the voltage sum obtained
by the binning (e.g., adding the values of multiple voltage
signals) to the temperature signal, e.g., the digital value
associated with one voltage sum corresponding to one temperature
value or the digital values associated with multiple voltage sums
corresponding to one identical temperature value. As the binned
voltage sum and the voltage signal without the binning have
different conditions, the second calibration calculating circuit
208 is further provided to perform the conversion from digital
values to temperature values. The memory 210 preferably further
records the corresponding relationship or algorithm between the
digital value (or digital code) of voltage sum and the object
temperature Tobj such that when the digital value of one voltage
sum is received from the ADC 206, a corresponding temperature value
is calculated by the second calibration calculating circuit 208. In
one non-limiting aspect, the second calibration calculating circuit
208 outputs only the object temperature Tobj without outputting the
ambient temperature Tamb.
[0041] The thermal detection device 200 includes, for example, a
multiplexer or a switching element used to transfer the digital
value of voltage signals to the first calibration calculating
circuit 207, and transfer the digital value of voltage sums to the
second calibration calculating circuit 208. In one non-limiting
aspect, the thermal detection device 200 includes two ADC used to
convert the digital signal of Vobj and Vamb, respectively.
[0042] Accordingly, the thermal detection device 200 outputs
digital values (associated with Vobj only), object temperatures
Tobj and ambient temperatures Tamb at predetermined frequencies
identical to or different from one another, wherein the
predetermined frequency is, for example, 1 to 3 times per second
according to different applications. In the present disclosure, the
digital value outputted by the thermal detection device 200
includes the detection result of the thermal sensor 201 to be used
later (described below by an example) without the detection result
of the ambient temperature sensor 209. The detection result of the
ambient temperature sensor 209 is outputted as ambient temperature
Tamb, which is converted by the first calibration calculating
circuit 207.
[0043] The thermal detection device 200 of the present disclosure
further includes other circuits such as a power management circuit
and an oscillation circuit, and details thereof are known to the
art and thus not described herein. Different applications of the
thermal detection device 200 are described hereinafter.
[0044] Referring to FIG. 4, it is a schematic block diagram of an
auto detection system 400 according to one embodiment of the
present disclosure. The auto detection system 400 includes a
thermal detection device 200 and a host 40 coupled to each other in
a wired or wireless manner to communicate therebetween. The thermal
detection device 200 may use that shown in FIG. 2, and is arranged,
for example, on an electronic device 46 to output digital values,
object temperatures Tobj and ambient temperatures Tamb according to
the detection result thereof. The host 4 is a computer device
equipped with a central processing unit (CPU) and/or a
microcontroller unit (MCU) such as, for example, a desktop
computer, a notebook computer, a tablet computer, a smart phone, a
central server or the like. The host 4 is direct1y integrated with
a display device 42 and/or a speaker 44, or coupled with the
display device 42 and/or the speaker 44 in a wired or wireless
manner. In this way, the host 4 receives the digital values, object
temperatures Tobj and ambient temperatures Tamb from the thermal
detection device 200 to control the display device 42, the speaker
42 and/or the electronic device 46, which is, for example, a device
that the thermal detection device 200 is applied to.
[0045] Referring to FIG. 5, it is a schematic diagram of the
application of an auto detection system 400 according to a first
embodiment of the present disclosure. In the first embodiment, at
least one thermal detection device 200 (e.g., 5 thermal detection
devices being shown in FIG. 5 at different positions) is arranged
at a ceiling or close to the ceiling of an elevator cabin 50, and
each thermal detection device 200 has its own field of view FOV
(for simplification only one being shown). In the first embodiment,
as the auto detection system 400 is used to detect whether the
elevator cabin 50 has a person therein or not, the FOV of the
thermal detection device 200 preferably covers only an inside area
of the elevator cabin 50 without covering the area outside an
entrance (i.e. outside the elevator) of the elevator cabin 50. In
the present disclosure, the thermal detection device 200 is
preferably arranged at two sides above the entrance or at a central
area of the ceiling of the elevator cabin 50. Preferably, the field
of view FOV of the thermal detection device 200 does not cover the
entrance of the elevator cabin 50 to reduce the influence from the
opening and closing of the cabin door.
[0046] As mentioned above, each thermal detection device 200
outputs digital values, object temperatures Tobj and ambient
temperatures Tamb respectively at a predetermined frequency to the
host 40. The host 40 is located, for example, at a central control
room, a guardroom or held by a staff outside the elevator cabin 50
for the staff to monitor whether there is a person in the elevator
cabin 50 or not via the display device 42, the speaker 44, lamps or
other indicating means. In the present disclosure, the display
device 42 does not show the inner image of the elevator cabin 50,
and the indication of whether there is a person in the elevator
cabin 50 or not is shown by words or graphs on the display device
42 for the privacy protection.
[0047] In the first embodiment, the thermal detection device 200
includes a single thermopile sensor or a thermopile sensor array.
For the thermopile sensor array case, the thermal detection device
200 has a pixel array (e.g., 201) for outputting multiple voltage
signals Vobj (or called a frame) every sampling period. As
mentioned above, the addition circuit 205 is used to sum up a part
or all of the multiple voltage signals Vobj (more specifically the
amplified voltage signals) to generate a voltage sum(s). The ADC
206 is used to convert the voltage signal Vobj and the voltage sum
into the digital value. The first calibration calculating circuit
207 is used to convert and output the object temperature Tobj
according to the digital value associated with the voltage signal
Vobj. The second calibration calculating circuit 208 is used to
convert and output the object temperature Tobj according to the
digital value associated with the voltage sum. It is appreciated
that the resolution of the digital value is determined by the
resolution of the ADC 206, e.g., 0-255, but not limited to.
[0048] After receiving the detection result from the thermal
detection device 200, the host 40 calculates a slope between two
digital values, a fluctuation degree of multiple digital values and
a temperature variation of the object temperatures Tobj
corresponding to each thermal detection device 200, and then
identifies whether the elevator cabin 50 has a person therein or
not according to the calculated slope, fluctuation degree and
temperature variation. The host 40 performs the identification
according to the outputted parameter of each thermal detection
device 200, respectively, to obtain multiple identification
results. The method of identifying the existence of a person
according to one thermal detection device 200 is illustrated
hereinafter.
[0049] Referring to FIG. 6, it is a schematic diagram of a
variation of the object temperature Tobj when there is a person and
no person in an elevator cabin 50. It is seen from FIG. 6 that when
a person enters or leaves the elevator cabin 50, the object
temperature Tobj changes to have a temperature variation, e.g.,
.DELTA.T1, .DELTA.T2 and .DELTA.T3, wherein values of .DELTA.T1,
.DELTA.T2 and .DELTA.T3 are identical to or different from each
other according to the human height, human body temperature,
ambient temperature or other environmental conditions. When the
temperature variation (increment or decrement) exceeds a
temperature threshold, it is able to identify a person in/out. In
the present disclosure, the temperature variation is, for example,
a difference between two adjacent (in timeline) object temperatures
Tobj outputted by the thermal detection device 200, two object
temperatures Tobj separated by a predetermined time interval, or a
difference between a current object temperature (e.g., at time t2)
outputted by the thermal detection device 200 and a recorded object
temperature (e.g., at time t1) stored when the elevator cabin 50
has no person therein.
[0050] In other words, the host 40 preferably includes a memory 401
used to record an object temperature Tobj when there is no person
in the elevator cabin 50 (e.g., at time t1) as a reference
temperature to avoid error caused by the ambient temperature
variation. The host 40 updates the reference temperature every
predetermined time when the elevator cabin 50 continuously has no
person therein, or the host 40 updates the reference temperature
(e.g., at time t3) after a person(s) enters and leaves the elevator
cabin 50 to increase the identification accuracy.
[0051] However, it is noticed that there are many reasons that can
influence the object temperature Tobj. Accordingly, the present
embodiment further uses other detected parameters in addition to
the object temperature Tobj to identify whether the elevator cabin
50 has a person therein or not.
[0052] Referring to FIG. 7A, it is a schematic diagram of the
digital value (associated with the voltage signal Vobj or voltage
sum) fluctuation (indicated by solid line) and the slope variation
(indicated by dotted line) when there is no person in an elevator
cabin 50. The reason of using the digital value to perform the
identification is that the resolution of digital value can be set
to be larger than the resolution of temperature value to obtain
more accurate identification result.
[0053] In the first embodiment, the host 40 calculates a slope
between two digital values, wherein said two digital values are two
adjacent (in timeline) digital values outputted by the thermal
detection device 200. As mentioned above, the thermal detection
device 200 is set to output 1 to 3 digital values per second. When
the slope between two digital values exceeds a slope threshold
value or a slope threshold range, e.g., TH1 and TH2 in FIG. 7A, it
means that the door of the elevator cabin 50 is opened and a person
might enter or leave the elevator cabin 50. It is seen from FIG. 7A
that when the door of the elevator cabin 50 opens and closes, the
slope have an obvious change (e.g., exceeding a threshold).
[0054] In addition, to increase the identification accuracy, the
host 40 further identifies whether a fluctuation degree of multiple
digital values exceeds a code variation threshold. For example, the
fluctuation degree is preferably a standard deviation, shown as
Stdev in FIG. 7A, of multiple digital values within a predetermined
time interval after the slope between the two digital values
exceeds the slope threshold. In one aspect, Stdev is a standard
deviation of multiple digital values within the predetermined time
interval after the slope changes back to be within a predetermined
threshold range (e.g., between TH1 and TH2). It is seen from FIG.
7A that the slope exceeds the predetermined threshold range when
the cabin door opens and then goes back to be within the
predetermined threshold range after the cabin door closes.
[0055] Referring to FIG. 7B together, it is a schematic diagram of
the digital value fluctuation (indicated by solid line) and the
slope variation (indicated by dotted line) when there is a person
in an elevator cabin 50. It is seen from FIGS. 7A and 7B that the
slope between two digital values exceeds the predetermined
threshold range (e.g., between TH1 and TH2) when the door of the
elevator cabin 50 opens (no matter whether there is a person
entering or leaving) and then goes back to be within the
predetermined threshold range after the cabin door closes.
Accordingly, it is not easy to identify the entering/leaving person
only according to the slope variation. But it is seen from FIGS. 7A
and 7B that when there is a person in the elevator cabin 50, the
fluctuation degree Stdev of multiple digital values (e.g., FIG. 7B)
within a predetermined time interval (e.g., 3-10 seconds, but not
limited to) is larger than the fluctuation degree Stdev when there
is nobody in the elevator cabin 50 (e.g., FIG. 7A). The reason is
considered that the person in the elevator cabin 50 causes a larger
disturbance to the temperature. Accordingly, the first embodiment
performs the human identification using 3 parameters to effectively
improve the identification accuracy. In the case of FIGS. 7A and
7B, a code variation threshold is set, for example, as 1.0
code.
[0056] It should be mentioned that the fluctuation degree is not
limited to be calculated by using the standard deviation, and may
be obtained by calculating other parameters that can be used to
indicate the fluctuation of the digital values.
[0057] Referring to FIG. 8, it is an operational flow chart of an
auto detection system 400 according to a first embodiment of the
present disclosure, including the steps of: generating temperature
values and digital codes (Step S81); comparing a code slope with a
slope threshold THa (Step S82); comparing a code fluctuation with a
code variation threshold THb (Step S83); comparing a temperature
variation with a temperature threshold THc (Step S84); and
identifying whether an elevator cabin has a person or not (Steps
S85-S86), wherein THa, THb and THc indicate a single value or a
value range, respectively.
[0058] Referring to FIGS. 4 to 8 together, the thermal detection
device 200 first1y sends the detected digital values (i.e. values
of digital codes) and object temperatures Tobj to the host 40, Step
S81.
[0059] In this embodiment, the host 40 identifies the elevator
cabin 50 having a person therein only when the slope between two
digital values exceeds a slope threshold or threshold range
(referring to FIGS. 7A and 7B), the fluctuation degree Stdev of
multiple digital values exceeds a code variation threshold or
threshold range (referring to FIGS. 7A and 7B), and the temperature
variation exceeds a temperature threshold or threshold range
(referring to FIG. 6), Step S82-S85. When any one of the Steps
S82-S84 is not true, the elevator cabin 50 is identified having no
person therein, Step S86.
[0060] No matter what is the identification result, the host 40
indicates whether the elevator cabin 50 has a person or not via a
coupled indication device (e.g., display device 42, speaker 44
and/or lamp), or via a coupled mobile device (e.g., smart phone or
smart watch).
[0061] In this embodiment, the host 40 further detects whether the
temperature in the elevator cabin 50 is normal or abnormal
according to the ambient temperature Tamb. If the ambient
temperature Tamb is too high or too low, a warning message is
indicated via the indication device or the mobile device. In
addition, the host 40 further adjusts the slope threshold, the code
variation threshold and/or the temperature threshold according to
the ambient temperature Tamb to eliminate the interference brought
by the environment change.
[0062] In one non-limiting embodiment, if the auto detection system
400 includes more than one thermal detection device 200. When
identifying that the elevator cabin 50 has a person therein
according to one of the multiple thermal detection devices 200, the
host 40 identifies that the elevator cabin 50 is occupied by a
person(s). The host 40 is not necessary to identify the elevator
cabin 50 being occupied after all thermal detection devices 200 are
identified to have a person therein.
[0063] In one non-limiting embodiment, if the auto detection system
400 includes a thermopile sensor array. When identifying that the
elevator cabin 50 has a person therein according to a predetermined
number of pixels or pixel regions (e.g., sub-regions shown in FIGS.
3C-3D) of a pixel array of the thermopile sensor array, the host 40
identifies that the elevator cabin 50 is occupied by a person(s),
wherein the predetermined number is smaller than a pixel number or
a region number of the pixel array. The host 40 is not necessary to
identify the elevator cabin 50 being occupied after all pixels or
pixel regions are identified to have a person therein. The method
of identifying a person based on each pixel or pixel region is
referred to FIG. 8.
[0064] In another non-limiting aspect, one pixel of the thermopile
sensor array is turned on at first, and when the object temperature
Tobj detected by the one pixel exceeds a temperature threshold, the
rest pixels are then turned on.
[0065] In the first embodiment, after the elevator cabin 50 is
identified to have a person in Step S85, the host 40 continuously
identifies whether the person leaves or not according the digital
values and object temperatures Tobj sent from the thermal detection
device 200 based on the Steps S82 and S83. For example in FIG. 7B,
when the cabin door is opened and a person leaves the elevator
cabin 50, the curves in FIG. 7B change to FIG. 7A to cause the
fluctuation degree Stdev to be smaller than THb. In this way, the
host 40 confirms that the elevator cabin 50 has no person therein.
The host 40 further confirms that a person leaves the elevator
cabin 50 according to FIG. 6. As mentioned above, the host 40
updates the reference temperature of the elevator cabin 50 (as
shown in FIG. 6 temperatures at times t1 and t3 having different
values) to be used in the next round of identification.
[0066] In other aspects, the auto detection system 400 further
includes at least one thermal detection device 200 arranged outside
the elevator cabin 50 to monitor the elevator shaft to identify
whether there is a person in the elevator shaft.
[0067] Referring to FIG. 9, it is a schematic diagram of an auto
detection system 400 according to a second embodiment of the
present disclosure. In this embodiment, the auto detection system
400 is applied to the urine-wet detection of a diaper. Compared
with the conventional urine-wet detection by using a moisture
sensor, the casing of the auto detection system 400 of the present
disclosure does not have an opening to allow the moisture to come
in such that an enclosed structure is formed without being
influenced by the sweat moisture. The thermal detection device 200
is arranged at different positions to be suitable for male products
or female products.
[0068] The auto detection system 400 of this embodiment also
includes a thermal detection device 200 and a host 40 coupled to
each other. As shown in FIG. 9, the thermal detection device 200 is
arranged on the diaper 90 and used to output digital values at a
predetermined frequency. In this embodiment, the auto detection
system 400 outputs or does not output object temperatures Tobj
according to different applications. The thermal detection device
200 also includes a single thermopile sensor or a thermopile sensor
array without particular limitations. When the thermal detection
device 200 adopts the thermopile sensor array, the thermal
detection device 200 also performs the aforementioned binning
procedure on a part of or all multiple voltage signals outputted by
the thermal sensor 201 thereof.
[0069] The host 40 communicates with the thermal detection device
200 in a wired or wireless manner. Examples of the thermal
detection device 200 and the host 40 have been described above, and
thus only the operating method thereof are described
hereinafter.
[0070] Referring to FIG. 10, it is an operational flow chart of an
auto detection system 400 according to a second embodiment of the
present disclosure, including the steps of: generating digital
codes (Step S101); comparing a code slope with a slope threshold
THs (Step S102); conforming whether a continuous time exceeds a
time threshold THt (Step S103); and determining whether to give a
warning or not (Steps S104-S105).
[0071] Step S101: The thermal detection device 200 disposed in the
diaper 90 has, for example, a press button or a switch. When the
diaper 90 is worn on a human body, the thermal detection device 200
is activated to operate by using the press button or the switch; or
the thermal detection device 200 starts to operate after a
connection between the thermal detection device 200 and the host 40
is accomplished. Then, the host 40 receives the digital values
generated by the ADC 206 of the thermal detection device 200. In
this embodiment, the digital values are associated with the voltage
signal or the voltage sum depending on the type of the thermopile
sensor being used. As it is possible to set the digital values to
have higher resolution than the object temperatures Tobj, the
digital value is selected for the urine-wet detection. According to
different implementation, the host 40 further receives object
temperatures Tobj from the thermal detection device 200 for double
check or other identifications.
[0072] Step S102: After receiving the digital values sequentially,
the host 40 (e.g., the processor thereof) calculates a slope
between two digital values to be compared with a slope threshold
THs. In one aspect, a time interval for calculating the slope
between the two digital values is between, for example, 0.5 and 1.5
seconds i.e., a period of outputting the digital values is between
0.5 and 1.5 seconds. Preferably, when a different time interval is
selected, the slope threshold THs is also changed. When the slope
is larger than the slope threshold THs, the Step S103 is entered;
otherwise the Step S105 is entered and no warning is provided.
[0073] In another aspect, the host 40 identifies whether the
calculated slope is between a predetermined range, e.g., larger
than the slope threshold THs and smaller than another slope
threshold. The another slope threshold is for preventing error due
to the slope variation caused by other reasons since the urine
temperature is generally between a predetermined range.
[0074] Step S103: When identifying that the slope between two
digital values is larger than a slope threshold THs or within a
predetermined range, the host 40 then identifies whether the slopes
between multiple sets of two digital values within a predetermined
time interval (e.g., 5-7 seconds) are continuously larger than the
slope threshold THs or within the predetermined range. When the
calculated multiple slopes are larger than the slope threshold THs
or within the predetermined range longer than the time interval
THt, the Step S104 is entered; otherwise the Step S105 is entered
and no warning is provided. In this embodiment, the urine-wet is
confirmed only when multiple slopes are larger than the slope
threshold THs or within the predetermined range for a predetermined
time interval so as to avoid error due to the sensor falling off or
diaper being taken off.
[0075] In another aspect, the predetermined ranges of the slope in
Steps S102 and S103 are different. For example, in Step S103 the
predetermined range is set as TH11<slope<Thu1, and in Step
S103 the predetermined range is set as TH12<slope<Thu2,
wherein Thu1>Thu2 and TH11<TH12, but not limited thereto.
[0076] Step S104: The host 40 generates a prompt signal to the
indication device, e.g., the display device 42 and/or the speaker
44, or to a mobile device, e.g., a smart phone, to indicate a
prompt message, e.g., changing a new diaper.
[0077] In some aspects, the thermal detection device 200 further
outputs object temperatures Tobj or ambient temperatures Tamb to
the host 40. The host 40 generates a warning signal when the object
temperatures Tobj or the ambient temperatures Tamb exceed a
predetermined range. For example, when the object temperatures Tobj
or the ambient temperatures Tamb are too high, e.g., much higher
than the urine temperature (e.g., Tobj or Tamb=40 to 45 degrees),
the host 40 informs the indication device or the mobile device,
using the warning signal, to generate a warning message such as
images or sounds.
[0078] In addition, the host 40 of the second embodiment further
double checks the urine-wet condition in conjunction with the
fluctuation, difference, slope, waveform or the standard deviation
of the object temperatures Tobj and/or the digital values within a
predetermined time interval.
[0079] In addition, the host 40 of the second embodiment further
identifies the wearing state of the diaper 90 according to whether
the object temperature Tobj and/or the digital value is within a
predetermined operation range.
[0080] Referring to FIG. 11, it is a schematic diagram of an auto
detection system 400 according to a third embodiment of the present
disclosure. In this embodiment, the auto detection system 400 is
applied to the stove detection in the kitchen, e.g., overheating,
forgetting to turn off the stove, cooking assistance or the like.
The auto detection system 400 includes at least one thermal
detection device 200. A number of the thermal detection device 200
is determined according to the area to be detected without
particular limitations.
[0081] The auto detection system 400 of this embodiment also
includes a thermal detection device 200 and a host 40 coupled to
each other. The thermal detection device 200 has a field of view
FOV covering the stove 100 and outputs object temperatures Tobj at
a predetermined frequency. It should be mentioned that although
FIG. 11 shows that the thermal detection device 200 is arranged
right above the stove 100, the present disclosure is not limited
thereto. The thermal detection device 200 may be arranged at any
suitable angle as long as the FOV thereof covers the stove 100, and
the stove 100 is not limited to heat a pot.
[0082] The host 40 is coupled to the thermal detection device 200
in a wired or wireless manner to receive object temperatures Tobj
for controlling an extraction fan, the stove fire, a display device
and/or other equipment in the kitchen according to the object
temperatures Tobj. The host 40 is wired or wirelessly coupled to
the electronic device 46 or integrated therein.
[0083] In one non-limiting aspect, the host 40 and the thermal
detection device 200 are both integrated in the extraction fan. The
host 40 is used to turn on the extraction fan when identifying that
the object temperature Tobj exceeds a room temperature threshold
(indicating the stove being turned on). The host 40 is further used
to automatically adjust the wind strength of the extraction fan
according to a variation of the object temperature Tobj (indicating
the stove changing). In the case that the host 40 are separated
from the extraction fan, the host 400 still automatically controls
the extraction fan in a wired or wireless manner or informs a user
to turn on the extraction fan via a display device 42.
[0084] In another non-limiting aspect, the host 40 is further used
to control the indication device (e.g., including the display
device 42 and/or speaker 44) to show a warning message when
identifying that the object temperature Tobj exceeds a high
temperature threshold, wherein the indication device is embedded in
the host 40 or the electronic device 46, or separated
therefrom.
[0085] In another non-limiting aspect, the host 40 turns off the
stove when identifying that the FOV of the thermal detection device
200 does not have any movement of a human body for a predetermined
time interval. In this aspect, the thermal detection device 200
preferably includes a thermopile sensor array for outputting a
thermal frame containing multiple object temperatures Tobj (e.g.,
each pixel outputting one object temperature) at a predetermined
frequency. The host 40 controls the display device according to the
thermal frame to show the multiple object temperatures by a
2-dimentional (2D) image, as shown in FIGS. 12A and 12B for
example. In FIG. 12A, each rectangular region indicates a detected
value of one pixel or one pixel region. For example, the display
device 42 direct1y shows the object temperatures Tobj (e.g., values
in every rectangular region in FIG. 12A) at the corresponding
regions. In other aspects, the display device 42 shows high/low
temperatures by different colors or brightness as FIG. 12B without
showing values of the object temperatures Tobj.
[0086] In this way, the host 40 performs various identifications
and gives a corresponding prompt message according to the thermal
frame or the 2D image. For example, if the thermal frame or the 2D
image does not contain the movement of a heating object (e.g.,
including a human body or heated shovel), it is identified that the
FOV of the thermal detection device 20 does not have movement of a
human body.
[0087] For example, in preheating a pot, when identifying that at
least one of the multiple object temperatures Tobj of the thermal
frame is larger than or equal to a heating threshold, the host 40
controls the indication device to indicate the message of a target
temperature being reached so as to remind the user to put
ingredients in the pot. For example, when identifying that the
uniformity of the multiple object temperatures Tobj of the thermal
frame is lower than a uniformity threshold, the host 40 controls
the indication device to show the message of nonuniform temperature
to remind the user to turn over the ingredients.
[0088] If the display device 42 shows a current temperature
distribution real-timely as FIGS. 12A and 12B, the user can know
the current operation temperature through the display device
42.
[0089] In one non-limiting aspect, the thermal detection device 200
further outputs ambient temperatures Tamb to the host 40. When
identifying that the ambient temperatures Tamb exceed a
predetermined temperature threshold, the host 40 controls the
cooling equipment such as a cooling fan or air conditioner to
decrease the temperature in the kitchen.
[0090] It is appreciated that the numbers, including temperatures,
digital values, pixel numbers and thresholds, mentioned in the
above embodiments are only intended to illustrate but not to limit
the present disclosure. Although the above embodiments are
described in the way that the host 40 informs only the display
device, a speaker and/or a mobile device as examples, the present
disclosure is not limited thereto. In other aspects, the host 40
informs other electronic devices in a smart home according to the
calculated and identified results.
[0091] For example, the thermal detection device 200 of the present
disclosure is arranged on a hair dryer for detecting the hair
temperature during operation to accordingly adjust the wind
strength and/or the wind temperature, e.g., by adjusting the
current flowing through the heating wire of the hair dryer. When
the hair temperature (e.g., identified by the host 40 according to
the object temperature Tobj) exceeds a predetermined temperature
threshold, the wind strength and/or the wind temperature is
decreased to prevent the hair from being damaged. On the contrary,
the wind strength and/or the wind temperature is increased.
[0092] For example, the thermal detection device 200 of the present
disclosure is arranged on an electric radiator for detecting the
skin temperature during operation to accordingly adjust the
radiation temperature and/or the wind temperature, e.g., by
adjusting the current flowing through the heating wire of the
electric radiator. When the skin temperature (e.g., identified by
the host 40 according to the object temperature Tobj) exceeds a
predetermined temperature threshold, the radiation temperature
and/or the wind temperature is decreased to improve the user
experience. On the contrary, the radiation temperature and/or the
wind temperature is increased.
[0093] In one aspect, the thermal detection device 200 of the
present disclosure is used as an optical sensor 320 or 520 in FIGS.
13-19 to be arranged on a circuit board and covered by a front
cover.
[0094] FIGS. 13, 14, 15 and 16 are schematic diagrams of an optical
sensor assembly 300 according to one embodiment of the present
disclosure. The optical sensor assembly 300 includes a circuit
board 310 (e.g., a printed circuit board or a flexible circuit
board), an optical sensor 320, a connector 330, and a front cover
340. FIG. 13 is a side view of the circuit board 310, the optical
sensor 320, and the connector 330. FIG. 14 is a rear view of the
front cover 340. FIG. 15 is a front view of the front cover 340
attached to the circuit board 310. FIG. 16 is another view of the
circuit board 310 on which the front cover 340 is not yet attached.
The connector 330 is attached to a back surface 352 of the circuit
board 310, and the front cover 340 is attached to a front surface
351 of the circuit board 310.
[0095] The optical sensor 320 is positioned on and electrically
connected to the circuit board 310. The connector 330 is positioned
on the circuit board 310. The connector 330 is used to transmit
electrical signals to and from the optical sensor 320. In addition,
the connector 330 is used to transmit electrical signals between
the optical sensor 320 and an external electronic device that
adopts the optical sensor assembly 300. The front cover 340 is
attached to the circuit board 310 and covers the optical sensor
320. The front cover 340 includes an optical element 345 used to
allow incident light of a predetermined wavelength to transmit
through the optical element 345 and condense the incident light
onto the optical sensor 320. The optical element 345 is a convex
lens or a Fresnel lens.
[0096] In one embodiment, an outer surface 353 of the optical
element 345 is a plane surface, and the convex lens or the Fresnel
lens is formed at an inner surface 354 of the optical element
345.
[0097] However, the present disclosure is not limited thereto. In
one non-limiting aspect, the optical element 345 is a transparent
layer used to guide incident light to the optical sensor 320
without condensing or diverging the incident light.
[0098] It should be mentioned that although FIG. 15 shows that the
outer surface 353 of the optical element 345 is substantially
parallel to the front surface 351 of the circuit board 310, the
present disclosure is not limited thereto. According to an incident
direction of the incident light, the outer surface 353 of the
optical element 345 is preferably tilted to be perpendicular to the
incident direction.
[0099] In one embodiment, the front cover 340, including the
optical element 345, is made of polypropylene or polyethylene. The
whole front cover 340, including the optical element 345, is
produced via injection molding as a single piece. However, the
present disclosure is not limited thereto. In one non-limiting
aspect, the optical element 345 is formed separately from the front
cover 340, and then squeezed into the front cover 340.
[0100] In another embodiment, the optical element 345 includes at
least one of a polypropylene film, a polyethylene film, a silicon
film, a germanium film, and a diamond-like carbon film.
[0101] In one embodiment, the optical sensor 320 is a far infra-red
thermal sensor used to detect a temperature of a thermal source.
The aforementioned predetermined wavelength of the incident light
is in a range from 8 micrometers to 12 micrometers, and the optical
element 345 is used to allow the incident light to transmit through
the optical element 345 with a transmittance in a range from 20% to
80%.
[0102] In another embodiment, the optical sensor 320 is an ambient
light sensor. The aforementioned predetermined wavelength of the
incident light is in a range from 390 nanometers to 700
nanometers.
[0103] The optical sensor 320 generates electrical signals by
detecting the incident light penetrating the optical element 345.
The connector 330 transmits the electrical signals to a processor
of an electronic device for predetermined control.
[0104] In one non-limiting aspect, the front cover 340 further
includes at least one alignment peg 341 (e.g., two alignment pegs
341 being shown in FIG. 14), and the circuit board 310 includes at
least one alignment hole 342 (e.g., two alignment hole 342 being
shown in FIG. 15) used to receive the at least one alignment peg
341, and the at least one alignment peg 341 is formed integrally
with the front cover 340. The front cover 340 further includes at
least one screw hole 343 used to receive at least one screw for
attaching and fixing the front cover 340 to the circuit board
310.
[0105] In the embodiment shown in FIGS. 14, 15 and 16, the front
cover 340 includes two alignment pegs 341 and two screw holes 343,
and the circuit board 310 includes two alignment holes 342. In
another embodiment, the front cover 340 includes more or less
alignment pegs 341 and more or less screw holes 343, and the
circuit board 310 includes more or less alignment holes 342.
[0106] The front cover 340 further includes a receiving cavity 347
used to accommodate the optical sensor 320 attached on the circuit
board 310. The front cover 340 is attached to the circuit board 310
via a water-proof and dust-proof adhesive, so that the circuit
board 310, the adhesive, and the front cover 340 around the
receiving cavity 347 form a sealed enclosure for accommodating and
protecting the optical sensor 320 from various hazards of the
ambient environment, such as water, dust, electrical damage and
mechanical damage. In the aspect that the front cover 340 is
combined with the circuit board 310 via adhesive, the at least one
screw hole 343 is not implemented.
[0107] It should be mentioned that although the front cover 340 is
shown to have curved edges between two protruding ends, it is only
to illustrate but not to limit the present disclosure. In other
embodiments, the front cover 340 has other shapes such as a
rectangular shape according to a receiving opening of the
electronic device adopting the optical sensor assembly 300.
[0108] FIGS. 17, 18 and 19 are schematic diagrams of an optical
sensor assembly 500 according to another embodiment of the present
disclosure. The optical sensor assembly 500 includes a circuit
board 510 (e.g., a printed circuit board or a flexible circuit
board), an optical sensor 520, a connector 540, a front cover 530,
and a back cover 550. FIG. 17 is a side view of the circuit board
510, the optical sensor 520, the connector 540, the front cover
530, and the back cover 550. FIG. 18 is a rear view of the circuit
board 510, the connector 540, the front cover 530, and the back
cover 550. FIG. 19 is a front view of the front cover 530.
[0109] In one non-limiting embodiment, when the circuit board 510
is fixed or sealed well with the front cover 530 to prevent dust
and water from contacting the optical sensor 520, the back cover
550 is not implemented.
[0110] The optical sensor 520 is attached to a front surface 581 of
the circuit board 510, and the optical sensor 520 is electrically
connected with the circuit board 510. The front cover 530 includes
a receiving cavity 560 used to receive at least the optical sensor
520. In one non-limiting embodiment, the receiving cavity 560
receives both the circuit board 510 and the optical sensor 520. The
front cover 530 further includes an optical element 531 used to
allow incident light of a predetermined wavelength to transmit
through the optical element 531 and condense the incident light
onto the optical sensor 520. The optical element 531 is a convex
lens or a Fresnel lens.
[0111] In one embodiment, an outer surface 583 of the optical
element 531 is a plane surface, and the convex lens or the Fresnel
lens is formed at an inner surface 584 of the optical element
531.
[0112] However, the present disclosure is not limited thereto. In
one non-limiting aspect, the optical element 531 is a transparent
layer used to guide incident light to the optical sensor 520
without condensing or diverging the incident light.
[0113] In one embodiment, the optical sensor 520 is a far infra-red
thermal sensor used to detect a temperature of a thermal source.
The aforementioned predetermined wavelength of the incident light
is in a range from 8 micrometers to 12 micrometers, and the optical
element 531 is used to allow the incident light to transmit through
the optical element 531 with a transmittance in a range from 20% to
80%.
[0114] In another embodiment, the optical sensor 520 is an ambient
light sensor. The aforementioned predetermined wavelength of the
incident light is in a range from 390 nanometers to 700
nanometers.
[0115] The front cover 530 further includes a curved sheet 533, a
planar frame 535 connected to and surrounding the curved sheet 533,
and a wall structure 570 positioned on the curved sheet 533. In
another embodiment, the wall structure 570 is connected to the
planar frame 535. The receiving cavity 560 is positioned in and
formed by the wall structure 570. The optical element 531 is a part
of the curved sheet 533. In one embodiment, the curved sheet 533
has a plane surface within a region of the optical element 531, and
the rest part of the curved sheet 533 has a curved surface.
[0116] The optical sensor 520 is aligned with the optical element
531. Preferably, the optical element 531 is parallel to a sensing
surface 585 of the optical sensor 520. In one aspect, the whole
curved sheet 533 is transparent to the incident light. In another
aspect, the curved sheet 533 is transparent to the incident light
only within a region of the optical element 531, and the rest part
of the curved sheet 533 is opaque or semi-opaque to the incident
light.
[0117] In one embodiment, the optical element 531 and the optical
sensor 520 are neither parallel nor perpendicular to the planar
frame 535, as shown in FIG. 17. The angle difference between the
planar frame 535 and the optical element 531 is determined based on
design requirements of the optical sensor assembly 500.
[0118] In another embodiment, the optical element 531 and the
optical sensor 520 are parallel to the planar frame 535. The
optical element 531 is a part of the curved sheet 533. The circuit
board 510 is attached to the wall structure 570. The shapes of the
curved sheet 533 and the wall structure 570 are arranged such that
the optical element 531, the optical sensor 520, and the circuit
board 510 (determined by a tile angle of the outer loop wall 572)
are all parallel. When the tile angle is changed, a light receiving
angle of the optical element 531 and optical sensor 520 is also
altered.
[0119] The wall structure 570 includes an inner loop wall 571
surrounding the optical element 531 and an outer loop wall 572
surrounding the inner loop wall 571. The inner loop wall 571 and
the outer loop wall 572 have different heights at different edges
of the front cover 530, e.g., lower at an upper edge and higher at
a lower edge to cause the optical sensor 520 to have an angle
difference with respect to the planar frame 535.
[0120] One end of the inner loop wall 571 is connected to the
curved sheet 533 and another end of the inner loop wall 571 has an
opening 576. One end of the outer loop wall 572 is connected to the
curved sheet 533 and another end of the outer loop wall 572 has an
opening 577. The area of the circuit board 510 is between the area
of the opening 576 of the inner loop wall 571 and the area of the
opening 577 of the outer loop wall 572. In other words, the area of
the circuit board 510 is larger than the area of the opening 576 of
the inner loop wall 571, and the area of the circuit board 510 is
smaller than the area of the opening 577 of the outer loop wall 572
so as to be accommodated in the outer loop wall 572.
[0121] The receiving cavity 560 includes a first cavity 561 for
receiving the optical sensor 520 and a second cavity 562 for
receiving the circuit board 510. The first cavity 561 is positioned
in the inner loop wall 571. The second cavity 562 is positioned in
the outer loop wall 572.
[0122] To enhance the mechanical strength, the wall structure 570
further includes a plurality of ridge walls 573 connecting the
inner loop wall 571, the outer loop wall 572 and the curved sheet
533. Each of the ridge walls 573 has an indent 574 on an edge 575
of that ridge wall 573 connecting the inner loop wall 571 and the
outer loop wall 572. The second cavity 562 is formed by the indents
574 of all of the ridge walls 573.
[0123] In one non-limiting embodiment, the indents 574 and the
second cavity 562 are not implemented. In this case, the circuit
board 510 is attached to the inner loop wall 571 and the ridge
walls 573 to seal the first cavity 561.
[0124] In one non-limiting embodiment, the ridge walls 573 are not
implemented. In this case, the opening 577 of the outer loop wall
572 defines the second cavity 562.
[0125] In one non-limiting embodiment, the inner loop wall 571 is
not implemented. In another one non-limiting embodiment, the outer
loop wall 572 is not implemented. In another one non-limiting
embodiment, both of the inner loop wall 571 and the outer loop wall
572 are not implemented.
[0126] According to FIG. 18, there are spaces between the ridge
walls 573, the inner loop wall 571 and the outer loop wall 572.
However, the present disclosure is not limited thereto. In one
non-limiting embodiment, the ridge walls 573 fill all the spaces
between the inner loop wall 571 and the outer loop wall 572 so that
the wall structure 570 is a thick and solid loop wall surrounding
the optical element 531 and the first cavity 561.
[0127] In one embodiment, the front cover 530, including the
optical element 531, is made of polypropylene or polyethylene. The
front cover 530, including the optical element 531 and the wall
structure 570, is produced via injection molding as a single piece.
However, the present disclosure is not limited thereto. In one
non-limiting aspect, the optical element 531 is formed separately
and has different materials from the front cover 530, and then
combined with the front cover 530.
[0128] In another embodiment, the optical element 531 includes at
least one of a polypropylene film, a polyethylene film, a silicon
film, a germanium film, and a diamond-like carbon film.
[0129] The connector 540 is attached to a back surface 582 of the
circuit board 510, and the connector 540 is electrically connected
to the circuit board 510. The connector 540 is used to transmit
electrical signals to and from the optical sensor 520. In addition,
the connector 540 is used to transmit electrical signals between
the optical sensor 520 and an external electronic device that
adopts the optical sensor assembly 500. The back cover 550 is
attached to the outer loop wall 572, for example, via a water-proof
and dust-proof adhesive. The back cover 550 is used to seal the
opening 577 of the outer loop wall 572. The back cover 550 has an
opening 555 used to expose an end 545 of the connector 540.
[0130] The optical sensor 520 generates electrical signals by
detecting the incident light penetrating the optical element 531.
The connector 540 transmits the electrical signals to a processor
of an electronic device for predetermined control.
[0131] In one embodiment, the circuit board 510 is attached to the
inner loop wall 571 and the ridge walls 573, for example, via a
water-proof and dust-proof adhesive. In this way, the circuit board
510, the inner loop wall 571, the curved sheet 533, and the optical
element 531 form a sealed enclosure for accommodating and
protecting the optical sensor 520 from various hazards of the
ambient environment, such as water, dust, electrical damage and
mechanical damage. The outer loop wall 572 and the back cover 550
provide additional protection for the optical sensor 520 against
the hazards of the ambient environment.
[0132] In one embodiment, the optical sensor assembly 500 is
applied to an electronic device. The front cover 530 further
includes at least one latching hook 532 configured for attaching
the optical sensor assembly 500 to the other parts of the
electronic device. In the embodiment shown in FIGS. 17, 18 and 19,
the front cover 530 includes two latching hooks 532. In another
embodiment, the front cover 530 includes more or less latching
hooks 532.
[0133] In one non-limiting embodiment, the optical sensor assembly
500 is attached to the electronic device by other means such as
screws or adhesive, and the at least one latching hook 532 is not
implemented.
[0134] It should be mentioned that although the front cover 530 is
shown to have a rectangular appearance, it is only to illustrate
but not to limit the present disclosure. In other embodiments, the
front cover 530 has other shapes such as a circular or ellipse
shape according to a receiving opening of the electronic device
adopting the optical sensor assembly 500.
[0135] In the present disclosure, the type of the connector 330 and
540 is not particularly limited as long as it is combinable to
another connector of an electronic device that adopts the optical
sensor assembly 300 and 500.
[0136] As mentioned above, in an auto detection system, using an
image sensor has a privacy concern and using a PIR motion sensor is
unable to detect a steady object. Therefore, the present disclosure
further provides an auto detection system using a thermopile sensor
(FIG. 4) and operating methods thereof (FIGS. 8 and 10) that have
broad applications such as the human detection in an elevator, the
urine-wet detection, the stove detection, the hair temperature
detection and the skin temperature detection.
[0137] Although the disclosure has been explained in relation to
its preferred embodiment, it is not used to limit the disclosure.
It is to be understood that many other possible modifications and
variations can be made by those skilled in the art without
departing from the spirit and scope of the disclosure as
hereinafter claimed.
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